Trays of the kind for use in mounting cases containing electrical equipment



3,316,456 AINING April 25, 1967 A. BARLOW TRAYS OF THE KIND FOR USE IN MOUNTING CASES CONT ELECTRICAL EQUIPMENT 3 Sheets-Sheet 1 Filed Oct. 5, 1965 A. BARLOW 3,316,456

ING CASES CONTAINING April 25,1967

TRAYS OF THE KIND FOR USE IN MOUNT ELECTRICAL EQUIPMENT 3 Sheets-Sheet 2 Filed Oct. 5, 1965 ALAN HARLOW-hu k,

flue, Rem/ 4 0% M A ril 25, 1967 A. BARLQW 3,316,456

TRAYS OF THE KIND FOR USE IN MOUNTING CASES CONTAINING ELECTRICAL EQUIPMENT Filed Oct. 5, 1965 5 Sheets-Sheet 3 55 4! J 54 J? 15 Z 4/ ALAN BARLUWJIhl/dhfik Ade, rmm Fl M 5M flf a'rne s United States Patent Ofiice 3,316,456 Patented Apr. 25, 1967 3,316,456 TRAYS OF THE KIND FOR USE IN MOUNTING CASES CONTAINING ELECTRICAL EQUIPMENT Alan Barlow, Cheltenham, England, assignor to S. Smith & Sons (England) Limited, London, England, a British company Filed Oct. 5, 1965, Ser. No. 493,056 Claims priority, application Great Britain, Oct. 9, 1964,

41,283/64 14 Claims. (Cl. 317100) This invention relates to trays of the kind for use in mounting cases containing electrical equipment.

It is common practice to provide the different units of an electrical system in separate cases and to mount the case's containing the electrical equipment side-by-side on a support framework. This practice has particular advantage in the aeronautical field, and in this field has led to wide-acceptance of a standard range of cases and of standard mounting arrangements, all with the object of minimizing wastage of space and allowing for a certain degree of standardization in the support frameworks provided in aircraft. The standard, which is referred to by the letters ATR (standing for Air Transport Radio), specifies rectangular cases of a maximum height of 7% inches and of a length which for long cases is some 19 /2 inches and for short cases is some 12 /2 inches Various widths of cases are specified, these being nominally expressed as fractions or multiples of a unit ATR-width of approximately ten inches, and typically the width of a /2 ATR case is five inches and the width of a ATR case just under 2 /2 inches.

For simplicity it is common practice to mount ATR cases side-by-side using trays bolted directly to cross-rails that are supported in the aircraft by means of anti-vibration mountings. Each tray provides an elongated guideway which is of a width just sufficient to receive the base of the case as a sliding fit. The case, with its base in the guide-way, is slid along the tray until appropriate mating is achieved between male and female electrical connectors that are carried at the rear of the case and tray and facilitate electrical connection to the equipment contained in the case. At least one forward-projecting spigot is carried at the rear of the tray to engage with a socket in the rear of the case and ensure alignment of the connectors with one another prior to their engagement. After the case has been pushed fully home with the connectors fully engaged with one another, it is locked to the tray by means of one or more releasable locking devices that are carried at the front of the tray and engage with the front of the case. This mounting of the case on the cross-rails using the tray is required to be sufficiently rigid to withstand any of the acceleration forces and vibrations that might be experienced in use, without undesirable fiexure of the case. Such a requirement is particularly difiicult to satisfy in those circumstances where cases (for example A ATR cases) of small dimension in width compared with their height are to be mounted, and it is an object of the present invention to provide a tray that may be used to satisfy the requirement in these circumstances.

According to the present invention, in a tray for use in mounting a case containing electrical equipment, a substantially rigid honeycomb structure lies between the base of the tray and the base of a guide-way that is provided in the tray for receiving the base of the case.

The honeycomb structure may lie within an elongated channel-member of U-shaped cross-section, the base of said channel-member providing the base of the tray with the cells of the honeycomb extending substantially normally therefrom. A second elongated channel-member of U-shaped cross-section may be provided so as to fit within the first-mentioned channel-member with the honeycomb structure sandwiched between the bases of two channel-members, said second channel-member providing the guide-way for the base of the case.

The honeycomb structure is preferably of metal.

According to a feature of the present invention a tray for use in mounting a case containing electrical equip ment, comprises two elongated and interfitting channelmembers which are both substantially of rectangular U- shaped cross-section and which are retained one within the other with their bases spaced apart from one another and with the upstanding sides of the two channel-members in close juxtaposition and extending from the bases all in the same direction, a metal honeycomb structure occupying the space between the bases and having its cells extending from one base to the other, and means for use in retaining the case with its base within the guide-way provided by the inner of the two channel-members.

An arrangement which includes a case for containing electrical equipment, mounted by means of a tray in acc'ordance with the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a perspective view of the arrangement showing the case mounted on the tray;

FIGURE 2 is a perspective view of the tray with the case removed;

FIGURE 3 is an exploded perspective view of one of four sub-cases of the case;

FIGURE 4 is a sectional side-elevation of part of the arrangement, illustrating the manner in which the case is locked to the tray by means of a device carried by the tray; FIGURE 5 is a view from underneath corresponding to FIGURE 4;

FIGURE 6 is a section of the tray alone, taken on the line VI-VI of FIGURE 4; and

FIGURE 7 is a front view of the lower part of a front panel of the case.

Referring to FIGURES l and 2, a ATR case 1 containing electrical equipment is mounted in an aircraft by means of a tray 2 which is bolted directly at its base to cross-rails 3 and 4 that are supported in the aircraft by means of anti-vibration mountings (not shown). The case 1 is retained in the tray 2 by means of a locking and jacking device 5 which is attached to the tray 2 and which engages with a bracket 6 screwed to the front panel 7 of an outer body structure 8 of the case 1. Electrical connection is made to the electrical equipment carried by the case 1 via four two-part electrical connectors at the rear of the case 1 and tray 2. The female connectors 9 of these four connectors are carried by a junction panel 10 that is mounted on the tray 2 and extends to the full height of the case 1 (only one of the four connectors 9 is shown), each connector 9 being partially accommodated in a respective cutout 11 of the panel 10. The four male connectors 12 (not shown in FIGURES 1 and 2) that mate with the connectors 9 project from the rear of the case 1 through cutouts in a rear panel 13 of the structure 8.

The male connectors 12 are carried respectively by four sub-cases or modules 14 which together carry all the electrical equipment contained by the case 1, and which are supported one above the other by pairs of longitudinal runners 15 (only one runner 15 is shown in FIGURE 1) that are welded along the interior of the structure 8. The modules 14 slide along the runners 15 into the case 1 from the front, and when each is fully home lie substantially wholly within the structure 8 with the male connectors 12 projecting through the rear panel 13 and with a front plate 16 of each abutting the front panel 7 of the structure 8. Each module 14 is retained in place within the structure 8 by two screws 17 that are carried by the front plate 16 of the module and screw into the front panel 7.

A spring-loaded spigot 18 projects forwardly from the top of the junction panel 10, and co-operates with a socket in the rear panel 13 to ensure that the male connectors 12 are correctly aligned with the female connectors 9 when the case 1 is slid into place along the tray 2. Three indexing-pins 19 also project forwardly from each female connector 9 to engage with co-operating sockets in the mating male connector 12 and to ensure final, and individual, alignment with one another of the male and female connectors on the modules 14 and panel respectively.

Referring now also to FIGURE 3, each of the four sub-cases or modules 14 comprises an elongated rectangular box-element 20 that provides a compartment 21 which is adapted to contain electrical equipment and which is closed on three sides only, and an elongated lid-element 22 that is adapted to fit to the box-element 20 and close the open fourth side of the compartment 21. The front plate 16, and a rear plate 23 carrying the male connector 12 of the module 14, close the two ends of the compartment 21 and provide shoulders 24 and 25 upon which to support the opposite ends of the lid-element 22. Three pairs of laterally-extending lugs 26 are provided at spaced positrons along the length of the box-element 20, the two lugs 26 of each pair projecting inwardly towards one another from opposite sides of the compartment 21. The shankportion of each lug 26 is terminated by an enlarged headportion.

The lid-element 22 is of substantially planar form having down-turned longitudinal edges 27 that are a close fit within the box-element 20 and are provided with three pairs of elongated slots 28. The slots 28 are adapted to be engaged by the shank-portions of the lugs 26 and are inclined to the lengthwise direction of the element 22 at an angle of some forty-five degrees, such that when the lid-element 22 is brought down to close the compartment 21 the final closing movement, with the lugs 26 engaging the slots 28, is constrained to movement having, in addition to a downward component, a component lengthwise of the box-element 20. When the lid-element 22 is fully engaged with the box-element 20, it is retained in position by means of a screw 29. The screw 29, which is provided with a cup-washer 30, screws into the front shoulder 24, and, when the lid-element 22 is fully engaged, is screwed into the shoulder 24 with a slot 31, in a central depression 32 at the front end of the lid-element 22, inserted under the cup-washer and the head of the screw 29. The lid-element 22 is in this manner clamped in place closing the compartment 21, removal of the lid-element 22 being restrained by the single screw 29 and the constraint imposed by the lugs 26 engaged with the slots 28.

The body of the box-element 20 between the front and rear plates 16 and 23 is formed by two channel-members 33 and 34 of rectangular U-shaped cross-section spotwelde'd back-to-back, the upper channel-member 33, having side-walls substantially longer than those of the lower channel-member 34, providing the compartment 21 for the electrical equipment. The front plate 16 carries a clip 35 for use in retaining an identification-tag (not shown) identifying in code the particular electrical equipment contained. Each of the four positions for the modules 14 in the case 1 is identified by the coded representation appropriate to the electrical equipment to be mounted at that position. The coded representation is provided on the front panel 7 (FIGURE 1) at the relevant position so as to be visible, when the appropriate module 14 is in place, through a corner cut-out 36 of the front plate 16 just above the identification clip 35 of the module.

Each sub-case or module 14 is easily withdrawn and inserted in the case 1 as required, withdrawal of the module simply involving unscrewing its screws 17 and then pulling it forwardly from the body structure 8 (thereby in this latter operation breaking the electrical connection to the module 14 and releasing it from the body structure 8), and insertion simply involving placing the module 14 on the appropriate pair of runners 15, pushing it backwardly as far as possible into the body 8, and then screwing up the screws 17 (thereby in this latter operation completing the establishment of electrical connection to the module 14 and securing it to the body structure 8). The modules 14 may each be provided with a handle (such as the handle 37 indicated in FIGURE 1 in broken outline on one module 14 only) to facilitate their withdrawal and insertion.

It is notable that the withdrawal and insertion of any module 14 does not involve any disturbance of the mount ing of any other module 14 or of the mounting of the case 1 on the tray 2.

Referring in addition now to FIGURES 4 to 6, the tray 2 is provided in basic construction by two elongated and interfitting channel members 40 and 41 which are both substantially of rectangular U-shaped cross-section and which are formed of aluminium-alloy sheeting of 24 S.W.G. (Standard Wire Gauge). The member 40 fits closely within the member 41 with its base 42 spaced from the base 43 of the member 41 and with the upstanding sides 44 and 45 of the two members 40 and 41 in contact and welded together along their length. The space be tween the bases 42 and 43 is occupied by a substantially rigid honeycomb structure 46 constructed of aluminium alloy strip and having its cells 47, of hexagonal crosssection, extending substantially normally from base 43 to base 42. The honeycomb structure 46 extends the whole length of the member 41, and, since each cell 47 is o en at both ends, does not to any material extent restrict the passage of air through the thickness of the tray 2 between a series of perforations 48 (FIGURE 2) in the base 42 and a corresponding series of perforations in the base 43 of the member 41. These perforations 48 allow for the passage of air from beneath the tray 2 into the case 1 via similar perforations in the base of the case 1.

Referring especially to FIGURES 4 and 5, the two ends of the space between the members 40 and 41 are closed, closure of the front end, where the member 40 overhangs the member 41, being achieved by an aluminium bracket piece 49. The bracket-piece 49 has pivoted to it a screwed shank 50 of the locking and jacking device 5. The device 5 also includes an internally-threaded sleeve 51 that is screwed on the shank 50, and a block 52 that is carried by the sleeve 51. The sleeve 51 is provided at its end remote from the bracket-piece 49 with a knurled finger-screw port-ion 53, and the block 52, which is rotatably mounted on the sleeve 51, has two pairs of pegs 54 and 55 projecting therefrom. The two pegs of each pair project in opposite directions to one another from opposite faces of the block 52, and are parallel to the pegs of the other pair.

When the case 1 has been slid into the tray 2 with its base in the guide-way provided by the member 40, with its rear panel 13 brought into initial engagement with the spigot 18, and with two rearwardly-projecting guideplns 56 (FIGURES 4 and 5) that are carried by the front panel 7 engaged beneath the bracket 49 at the front of the tray 2, the shank 50 of the device 5 is pivoted upwards to the horizontal position in which the block 52 enters a co-operating slot 57 (FIGURE 7) in the lower end of the front panel 7. The position of the sleeve 51 on the shank 50 is adjusted as necessary by rotating the fingerscrew portion 53 to bring the block 52 into the slot 57 with the pegs 54 and 55 to the front and rear respectively of the panel 7 (see FIGURES 4 and 5). The fingerscrew portion 53 is now rotated to move the block 52 along the shank 50 and urge the pegs 54 against shoulders 58 that are provided on either side of the slot 57 by the bracket 6 carried by the panel 7. Further rotation of the finger-screw portion 53 in the same sense acts via the pegs 54 to force the case 1 backwardly along the tray 2 to the position in which the case 1 is fully engaged with the spigot 18, and the male connectors 12 carried by the case 1 are fully mated with the connectors 9. 'In this position, further backward movement is not possible and final tightening of the finger-screw portion 53 firmly locks the case 1 to the tray 2.

When the case 1 is locked to the tray 2 in this manner, it is held firmly to the rails 3 and 4, the rigidity of the mounting, and the good frequency-response characteristics it exhibits, owing much to the provision of the honeycomb structure 46. The honeycomb structure 46 provides stiffness without undue extra weight, and in this respect is well suited to airborne applications. The locking device 5 holds the case 1 firmly in the tray 2 against the high acceleration forces that are likely to be experienced in airborne applications.

When it is desired to remove the case 1 from the tray 2, the finger-screw portion 53 is rotated in the sense to release the pegs 54 from the bracket 6 and bring the pegs 55 to bear in a groove 59 (FIGURE 4) at the rear of the front panel 7. 'Further rotation of the finger-screw portion 53 in the same sense urges the case 1 forwardly along the tray 2 to break the engagement of the male and female connectors 12 and 9 respectively, at the rear of the case 1. The spring-loading of the spigot 18 helps in the disengagement, the socket which in the rear panel 13 receives the spigot 18 being of insufiicient depth to accommodate its full length.

After disengagement of the case 1 from the connectors 9, the shank 50 is dropped downwards with the block 52 and pegs 55 released from the front panel 7. The case 1 may then be easily removed from the tray 2 using a handle 60 (FIGURE 1) provided at the top of the panel 7.

Although the invention has been described above more particularly in relation to a ATR case, the present invention is of wider application than this, being applicable to larger sizes of ATR case, and also even to cases that do not conform to the ATR standard.

I claim:

1. A tray for use in mounting a case containing electrical equipment upon a supporting structure, and for establishing electrical connection with electrical connector means carried externally by the case, comprising a first member for clamping to the supporting structure, a second member providing an elongated guide-way for receiving the case, means mounting the second member upon the first member, said mounting means including a substantially rigid honeycomb structure interposed between the first and second members to contribute rigidity to the tray, means carried by said second member for releasably retaining the case in the guide-way, and electrical connector means mounted on said second member to mate with the electrical connector means carried by the case so as to establish said electrical connection.

2. A tray according to claim 1 wherein the connector means mounted on said second member is mounted on the second member at a rear end of the guide-way, and the retaining means for releasably retaining the case in the guid-way is pivotally mounted on said second member at a front end of the guide-way, said retaining means comprising manually-rotatable screw means mounted on said second member at the front end of the guide-way and a pair of projections. carried by the screw means for engaging with the case to lock the case in the guide-way, said screw means being rotatable in one of two senses to carry the two projections in a direction towards the rear end of the guide-way for urging the case rearwardly in establishving mating engagement of the two connector means.

3. A tray according to claim 2 wherein said screw means carries a further pair of projections for engaging with the case for urging the case forwardly along the guide-way in breaking the engagement between the connector means, said screw means when rotated in the other of said two senses moving said further pair of projections forwardly with respect to said guide-way to break the engagement between the connector means.

4. A tray according to claim 2 wherein said retaining means comprises a screwed shank pivoted at the front end of the guide-way, an internally-threaded sleeve screwed on the shank, and a block which is rotatably mounted on the sleeve and which has at least two pegs projecting in opposite directions therefrom transversely of the shank.

5. A tray for use in mounting a case containing electrical equipment, comprising an elongated channel-memberof U-shaped cross-section, said channel-member having a base portion and sides upstanding from the base portion, a substantially rigid honeycomb structure lying within said channel-member with the cells of the hone comb structure extending substantially normally from the [base portion of the channel-member to contribute to the rigidity of the tray, a guide-way mounted on said honeycomb structure between said upstanding sides to receive the case, and a locking device mounted on the guide-way for releasably engaging with the case to retain the case in the guide-way.

6. A tray according to claim 5 wherein a second elongated channel-member of U-shaped cross-section fits within the first-mentioned channel-member with the honeycomb structure sandwiched between the two channel-members, said second channel-member providing said guide-way for the case.

7. A tray according to claim 5 wherein said honeycomb structure is of metal.

8. A tray for use in mounting a case containing electrical equipment, comprising two elongated and interfitting channel-members which are both substantially of rectangular U-shaped cross-section and which are retained one within the other with their bases spaced apart from one another and with the upstanding sides of the two channel-members extending from the bases all in the same direction, the upstanding sides of the inner of the two channel members fitting closely against and being bonded to the upstanding sides of the outer of the two channel members, a metal honeycomb structure occupying the space between the bases of the two channel-members and having its cells extending between said bases, and means connected to one of said channel members for retaining the case within the inner channel member.

9. A tray according to claim 8 including an electrical connector for establishing electrical connection with the electrical equipment contained by the case, and means mounting the electrical connector at one end of the inner channel member.

10. A tray according to claim 8 wherein the bases of the two channel-members are perforated for allowing air to pass to the case through the tray.

11. An arrangement for use in mounting electrical equipment on a supporting structure, comprising a case for containing the electrical equipment, and a tray for securing to said supporting structure, said tray including a base portion for abutting the supporting structure, a guide-way for receiving the case, means releasably retaining the case with its base in the guide-way, and a subtantially rigid honeycomb structure interposed in the tray between the guide-way and the base portion for contributing to rigidity of the tray.

12. An arrangement for use in mounting electrical equipment, comprising a case for containing the electrical equipment, and a tray having a guide-way along which to slide the case and means for releasably retaining the case in the guide-way, said tray including two elongated and interfitting channel-members which are both substantially of rectangular U-shaped cross-section, the two channel members each having a base together with sides upstanding from the base and being retained one within the other with their bases spaced apart from one another and with the upstanding sides of the two channel-members in close juxtaposition and extending from the bases all in the same direction, and a metal honeycomb structure occupying the space between the bases of the two channel- 7 8 members and having its cell extending between said References Cited by the Examiner bases- UNITED STATES PATENTS 13. An arrangement according to claim 12 wherein said case comprises an outer body structure, and a plu- 2,602,842 7/1952 Moms at 174 52 rality of elongated sub-cases that are releasably retaining 5 2345983 8/1960 V9881 et 317 100 X one above the other within the outer body structure. xizgs at t d' t 1 12 h 14 An arrangemen accor mg 0 calm W erem 3,198,990 8/1965 Katzin 317 1OO a first electrical connector is mounted at a rear end of the guide-way, and said case carries a second electrical connector for mating with said first connector when the case m ROBERT SCHAEFER Pnmary Exammer' is retained in said guide-way as aforesaid. M. GINSBURG, Assistant Examiner. 

11. AN ARRANGEMENT FOR USE IN MOUNTING ELECTRICAL EQUIPMENT ON A SUPPORTING STRUCTURE, COMPRISING A CASE FOR CONTAINING THE ELECTRICAL EQUIPMENT, AND A TRAY FOR SECURING TO SAID SUPPORTING STRUCTURE, SAID TRAY INCLUDING A BASE PORTION FOR ABUTTING THE SUPPORTING STRUCTURE, A GUIDE-WAY FOR RECEIVING THE CASE, MEANS RELEASABLY RETAINING THE CASE WITH ITS BASE IN THE GUIDE-WAY, AND A SUBTANTIALLY RIGID HONEYCOMB STRUCTURE INTERPOSED IN THE TRAY BETWEEN THE GUIDE-WAY AND THE BASE PORTION FOR CONTRIBUTING TO RIGIDITY OF THE TRAY. 